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.pdfContents |
ix |
5.4Algorithms of Linear Filtering and Extrapolation under Fixed Sample
Size of Measurements 156
5.4.1Optimal Parameter Estimation Algorithm by Maximal Likelihood
Criterion for Polynomial Target Track: A General Case........... |
157 |
5.4.2Algorithms of Optimal Estimation of Linear Target Track
Parameters......................................................................................... |
159 |
5.4.3Algorithm of Optimal Estimation of Second-Order Polynomial
Target Track Parameters |
162 |
5.4.4 Algorithm of Extrapolation of Target Track Parameters.................. |
166 |
5.4.5Dynamic Errors of Target Track Parameter Estimation Using
Polar Coordinate System 168
5.5 Recurrent Filtering Algorithms of Undistorted Polynomial Target |
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Track Parameters |
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170 |
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5.5.1 |
Optimal Filtering Algorithm Formula Flowchart............................. |
170 |
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5.5.2 |
Filtering of .....................................Linear Target Track Parameters |
174 |
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5.5.3 |
Stabilization ..........................Methods for Linear Recurrent Filters |
177 |
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5.5.3.1 Introduction of Additional Term into Correlation |
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Matrix of Extrapolation Errors |
178 |
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5.5.3.2 .......Introduction of Artificial Aging of Measuring Errors |
179 |
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5.5.3.3 ............................................................ |
Gain Lower Bound |
179 |
5.6 Adaptive Filtering ......Algorithms of Maneuvering Target Track Parameters |
179 |
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5.6.1 |
Principles of Designing the Filtering Algorithms |
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of Maneuvering Target Track Parameters |
179 |
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5.6.1.1 ................................................................... |
First Approach |
180 |
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5.6.1.2 ............................................................... |
Second Approach |
181 |
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5.6.1.3 ................................................................. |
Third Approach |
181 |
5.6.2 |
Implementation of Mixed Coordinate Systems under Adaptive |
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Filtering............................................................................................. |
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181 |
5.6.3 |
Adaptive Filtering Algorithm Version Based on Bayesian |
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Approach in Maneuvering Target |
186 |
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5.7 Logical Flowchart ........of Complex Radar Signal Reprocessing Algorithm |
192 |
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5.8 Summary and Discussion............................................................................... |
193 |
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References................................................................................................................. |
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199 |
Chapter 6 Principles of Control Algorithm Design for Complex Radar System |
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Functioning at Dynamical ..............................................................................Mode |
201 |
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6.1 Configuration and ...........................Flowchart of Radar Control Subsystem |
202 |
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6.2 Direct Control of .............................Complex Radar Subsystem Parameters |
207 |
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6.2.1 |
Initial Conditions............................................................................... |
207 |
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6.2.2 |
Control under Directional Scan in Mode of Searched |
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New Targets............................................................................... |
207 |
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6.2.3 |
Control Process under Refreshment of Target in Target |
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Tracing Mode.................................................................................... |
211 |
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6.3 Scan Control in New ................................................Target Searching Mode |
213 |
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6.3.1 |
Problem Statement .....and Criteria of Searching Control Optimality |
213 |
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6.3.2 |
Optimal Scanning ...........Control under Detection of Single Target |
214 |
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6.3.3 |
Optimal Scanning Control under Detection of Unknown |
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Number of .............................................................................Targets |
215 |
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6.3.4 |
Example of Scanning Control Algorithm in Complex Radar |
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Systems under Aerial Target Detection and Tracking 219
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Contents |
6.4 |
Power Resource Control under Target Tracking............................................ |
222 |
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6.4.1 Control Problem Statement............................................................... |
222 |
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6.4.2 Example of Control Algorithm under Target Tracking Mode.......... |
223 |
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6.4.3 Control of Energy Expenditure under Accuracy Aligning............... |
226 |
6.5 |
Distribution of Power Resources of Complex Radar System under |
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Combination of Target Searching and Target Tracking Modes |
228 |
6.6 |
Summary and Discussion............................................................................... |
231 |
References................................................................................................................. |
233 |
Part II Design Principles of Computer System for Radar Digital Signal Processing and Control Algorithms
Chapter 7 Design Principles of Complex Algorithm Computational Process |
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in Radar Systems.................................................................................................... |
237 |
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7.1 |
Design Considerations.................................................................................... |
237 |
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7.1.1 |
Parallel General-Purpose Computers................................................ |
238 |
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7.1.2 |
Custom-Designed Hardware............................................................. |
239 |
7.2 |
Complex Algorithm Assignment.................................................................... |
241 |
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7.2.1 Logical and Matrix Algorithm Flowcharts....................................... |
241 |
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7.2.2 |
Algorithm Graph Flowcharts............................................................ |
243 |
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7.2.3 Use of Network Model for Complex Algorithm Analysis................ |
246 |
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7.3 |
Evaluation of Work Content of Complex Digital Signal Processing |
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Algorithm Realization by Microprocessor Subsystems 249
7.3.1 |
Evaluation of Elementary Digital Signal Processing |
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Algorithm Work Content................................................................... |
249 |
7.3.2 |
Definition of Complex Algorithm Work Content Using |
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Network Model.................................................................................. |
250 |
7.3.3 |
Evaluation of Complex Digital Signal Reprocessing Algorithm |
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Work Content in Radar System |
252 |
7.4 Paralleling of Computational Process............................................................ |
257 |
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7.4.1 |
Multilevel Graph of Complex Digital Signal Processing Algorithm...... |
257 |
7.4.2 |
Paralleling of Linear Recurrent Filtering Algorithm |
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Macro-Operations............................................................................. |
263 |
7.4.3 |
Paralleling Principles of Complex Digital Signal Processing |
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Algorithm by Object Set |
265 |
7.5 Summary and Discussion............................................................................... |
267 |
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References................................................................................................................. |
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271 |
Chapter 8 Design Principles of Digital Signal Processing Subsystems Employed |
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by a Complex Radar System..................................................................................... |
273 |
8.1Structure and Main Engineering Data of Digital Signal Processing
Subsystems |
273 |
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8.1.1 |
Single-Computer Subsystem............................................................. |
273 |
8.1.2 |
Multicomputer Subsystem................................................................. |
276 |
8.1.3 Multimicroprocessor Subsystems for Digital Signal Processing...... |
278 |
8.1.4Microprocessor Subsystems for Digital Signal
Processing in Radar........................................................................... |
280 |
Contents |
xi |
8.2 Requirements for Effective Speed of Operation............................................ |
282 |
8.2.1 Microprocessor Subsystem as a Queuing System............................. |
282 |
8.2.2 Functioning Analysis of Single-Microprocessor Control |
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Subsystem as Queuing System 285
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8.2.3 Specifications for Effective Speed of Microprocessor |
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Subsystem Operation......................................................................... |
289 |
8.3 |
Requirements for RAM Size and Structure................................................... |
293 |
8.4 |
Selection of Microprocessor for Designing the Microprocessor Subsystems...... |
295 |
8.5Structure and Elements of Digital Signal Processing and Complex
Radar System Control Microprocessor Subsystems 296
8.6High-Performance Centralized Microprocessor Subsystem for Digital
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Signal Processing of Target Return Signals in Complex Radar Systems |
299 |
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8.7 |
Programmable Microprocessor for Digital Signal Preprocessing |
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of Target Return Signals in Complex Radar Systems |
301 |
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8.8 |
Summary and Discussion............................................................................... |
302 |
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References................................................................................................................. |
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306 |
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Chapter 9 |
Digital Signal Processing Subsystem Design (Example).......................................... |
309 |
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9.1 |
General Statements......................................................................................... |
309 |
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9.2 |
Design of Digital Signal Processing and Control Subsystem Structure......... |
310 |
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9.2.1 |
Initial Statements............................................................................... |
310 |
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9.2.2 |
Main Problems of Digital Signal Processing |
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and Control Subsystem................................................................... |
311 |
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9.2.3 |
Central Computer System Structure for Signal Processing |
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and Control........................................................................................ |
314 |
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9.3 |
Structure of Coherent Signal Preprocessing Microprocessor Subsystem...... |
315 |
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9.4 |
Structure of Noncoherent Signal Preprocessing Microprocessor Subsystem....... |
318 |
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9.4.1 |
Noncoherent Signal Preprocessing Problems................................... |
318 |
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9.4.2 |
Noncoherent Signal Preprocessing Microprocessor Subsystem |
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Requirements..................................................................................... |
321 |
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9.5 |
Signal Reprocessing Microprocessor Subsystem Specifications.................... |
322 |
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9.6 |
Structure of Digital Signal Processing Subsystem......................................... |
325 |
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9.7 |
Summary and Discussion............................................................................... |
327 |
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References................................................................................................................. |
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329 |
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Chapter 10 |
Global Digital Signal Processing System Analysis................................................... |
331 |
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10.1 |
Digital Signal Processing System Design...................................................... |
331 |
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10.1.1 |
Structure of Digital Signal Processing System................................. |
331 |
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10.1.2 |
Structure and Operation of Nontracking MTI.................................. |
332 |
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10.1.3 |
MTI as Queuing System.................................................................... |
335 |
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10.2 |
Analysis of “n – 1 – 1” MTI System.............................................................. |
339 |
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10.2.1 |
Required Number of Memory Channels........................................... |
339 |
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10.2.2 |
Performance Analysis of Detector–Selector..................................... |
340 |
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10.2.3 |
Analysis of MTI Characteristics....................................................... |
343 |
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10.3 |
Analysis of “n – n – 1” MTI System.............................................................. |
344 |
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10.4 |
Analysis of “n – m – 1” MTI System.............................................................. |
345 |
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10.5 |
Comparative Analysis of Target Tracking Systems....................................... |
347 |
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10.6 |
Summary and Discussion............................................................................... |
349 |
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References................................................................................................................. |
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349 |
xii |
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Contents |
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Part III Stochastic Processes Measuring in Radar Systems |
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Chapter 11 Main Statements of Statistical Estimation Theory................................................... |
353 |
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11.1 |
Main Definitions and Problem Statement...................................................... |
353 |
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11.2 |
Point Estimate and Its Properties................................................................... |
356 |
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11.3 |
Effective Estimations..................................................................................... |
358 |
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11.4 |
Loss Function and Average Risk.................................................................... |
359 |
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11.5 |
Bayesian Estimates for Various Loss Functions............................................ |
362 |
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11.5.1 |
Simple Loss Function........................................................................ |
363 |
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11.5.2 Linear Module Loss Function........................................................... |
364 |
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11.5.3 |
Quadratic Loss Function................................................................... |
365 |
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11.5.4 |
Rectangle Loss Function................................................................... |
366 |
11.6 |
Summary and Discussion............................................................................... |
366 |
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References................................................................................................................. |
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368 |
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Chapter 12 Estimation of Mathematical Expectation.................................................................. |
369 |
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12.1 |
Conditional Functional................................................................................... |
369 |
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12.2 |
Maximum Likelihood Estimate of Mathematical Expectation..................... |
373 |
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12.3 |
Bayesian Estimate of Mathematical Expectation: Quadratic |
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Loss Function |
381 |
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12.3.1 Low Signal-to-Noise Ratio (ρ2 1)................................................. |
383 |
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12.3.2 High Signal-to-Noise Ratio (ρ2 1)................................................. |
385 |
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12.4 |
Applied Approaches to Estimate the Mathematical Expectation.................. |
386 |
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12.5 |
Estimate of Mathematical Expectation at Stochastic Process Sampling....... |
397 |
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12.6 |
Mathematical Expectation Estimate under Stochastic Process |
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Amplitude Quantization |
408 |
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12.7 |
Optimal Estimate of Varying Mathematical Expectation of Gaussian |
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Stochastic Process |
413 |
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12.8 |
Varying Mathematical Expectation Estimate under Stochastic Process |
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Averaging in Time |
422 |
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12.9 |
Estimate of Mathematical Expectation by Iterative Methods........................ |
427 |
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12.10 |
Estimate of Mathematical Expectation with Unknown Period...................... |
430 |
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12.11 |
Summary and Discussion............................................................................... |
436 |
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References................................................................................................................. |
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439 |
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Chapter 13 Estimation of Stochastic Process Variance............................................................... |
441 |
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13.1 |
Optimal Variance Estimate of Gaussian Stochastic Process......................... |
441 |
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13.2 |
Stochastic Process Variance Estimate under Averaging in Time.................. |
449 |
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13.3 |
Errors under Stochastic Process Variance Estimate...................................... |
455 |
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13.4 |
Estimate of Time-Varying Stochastic Process Variance................................ |
460 |
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13.5 |
Measurement of Stochastic Process Variance in Noise................................. |
468 |
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13.5.1 Compensation Method of Variance Measurement............................ |
468 |
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13.5.2 |
Method of Comparison..................................................................... |
473 |
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13.5.3 Correlation Method of Variance Measurement................................. |
476 |
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13.5.4 Modulation Method of Variance Measurement................................ |
478 |
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13.6 |
Summary and Discussion............................................................................... |
484 |
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References................................................................................................................. |
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486 |
Contents |
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xiii |
Chapter 14 |
Estimation of Probability Distribution and Density Functions |
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of Stochastic Process............................................................................................ |
487 |
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14.1 |
Main Estimation Regularities........................................................................ |
487 |
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14.2 |
Characteristics of Probability Distribution Function Estimate...................... |
491 |
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14.3 |
Variance of Probability Distribution Function Estimate............................... |
495 |
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14.3.1 |
Gaussian Stochastic Process............................................................. |
495 |
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14.3.2 |
Rayleigh Stochastic Process.............................................................. |
499 |
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14.4 |
Characteristics of the Probability Density Function Estimate....................... |
504 |
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14.5 |
Probability Density Function Estimate Based on Expansion in Series |
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Coefficient Estimations |
509 |
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14.6 |
Measurers of Probability Distribution and Density Functions: |
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Design Principles |
514 |
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14.7 |
Summary and Discussion............................................................................... |
520 |
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References................................................................................................................. |
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521 |
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Chapter 15 |
Estimate of Stochastic Process Frequency-Time Parameters................................... |
523 |
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15.1 |
Estimate of Correlation Function................................................................... |
523 |
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15.2 |
Correlation Function Estimation Based on Its Expansion in Series............... |
531 |
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15.3 |
Optimal Estimation of Gaussian Stochastic Process Correlation |
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Function Parameter |
539 |
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15.4 |
Correlation Function Estimation Methods Based on Other Principles.......... |
554 |
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15.5 |
Spectral Density Estimate of Stationary Stochastic Process......................... |
561 |
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15.6 |
Estimate of Stochastic Process Spike Parameters.......................................... |
570 |
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15.6.1 Estimation of Spike Mean................................................................. |
571 |
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15.6.2 Estimation of Average Spike Duration and Average Interval |
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between Spikes.................................................................................. |
575 |
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15.7 |
Mean-Square Frequency Estimate of Spectral Density................................. |
579 |
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15.8 |
Summary and Discussion............................................................................... |
581 |
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References................................................................................................................. |
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582 |
Preface
The essential task in radar systems is to find an appropriate solution to the problems related to robust signal processing and definition of signal parameters. There are now a number of books and papers published in journals devoted to signal processing in noise in radar systems, but many key issues remain unsolved. New approaches to these problems allow us not only to summarize investigations but also to derive better quality of robust signal processing in noise in radar systems.
This book addresses the problems of robust signal processing in complex radar systems (CRSs) based on the generalized approach to signal processing in noise. The generalized approach to signal processing in noise is proposed based on a seemingly abstract idea: the introduction of an additional noise source that does not carry any information about the signal to improve the qualitative performance of CRSs. Theoretical and experimental studies lead to the conclusion that the proposed generalized approach to signal processing in noise in CRSs allows formulating a decision-making rule based on the determination of the jointly sufficient statistics of the mean and variance of the likelihood function. The use of classical and modern signal processing approaches allows us to define only the sufficient statistic of the mean of the likelihood function (or functional).
The presence of additional information about the statistical characteristics of the likelihood function leads to better qualitative performances of robust signal processing in CRSs in comparison with optimal signal processing algorithms of classical and modern theories. The generalized approach to signal processing allows us to extend the well-known boundaries of potential noise immunity set up by classical and modern signal processing theories. The use of CRSs based on the generalized approach to signal processing in noise allows us to obtain better detection performances, particularly in comparison with CRSs constructed on the basis of optimal and asymptotic optimal signal processing algorithms of classical and modern signal processing theories.
To better understand the fundamental statements and concepts of the generalized approach, the reader is invited to consult my earlier books: Signal Processing in Noise: A New Methodology (IEC, Minsk, 1998), Signal Detection Theory (Springer-Verlag, New York, 2001), Signal Processing Noise
(CRC Press, Boca Raton, FL, 2002), and Signal and Image Processing in Navigational Systems
(CRC Press, Boca Raton, FL, 2005).
The radar system is an important element in the field of electrical engineering. In university engineering courses, in general, the emphasis is usually on the basic tools used by the electrical engineer, such as circuit design, signals, solid state, digital processing, electronic devices, electromagnetics, automatic control, microwaves, and so on. In the real world of electrical engineering practice, however, these are only techniques, piece parts, or subsystems that make up some type of system employed for a useful purpose.
There are various aspects to radar system design. However, before a new radar system can be manufactured, a conceptual design has to be made to guide the actual development, taking into consideration the requirements of the radar system that must be customerand user-friendly. Conceptual design involves identifying the characteristics of the radar system in accordance with the radar equation and related equations and the general characteristics of the subsystems such as transmitter, antenna, receiver, signal processing, etc., that might be used. A conceptual design cannot be formed without a systems approach. Another important procedure is to define the structure of computer subsystems used in the radar for the purpose of implementing modern robust signal processing algorithms.
It should be noted that there are at least two ways in which a new CRS might be produced. One method is based on exploiting the advantages of some new invention, new technique, new device, or new knowledge. The invention of the microwave magnetron early in World War II is an example.
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Preface |
After the magnetron appeared, radar system design was different from what it had been before. The other, and probably more common, method for conceptual radar system design is to identify the function the new radar system has to perform, examine the various approaches available to achieve the desired capability, carefully evaluate each approach, and then select the one that best meets the needs within the operational and fiscal constraints imposed. This book discusses in detail these two methods that are based on a systems approach to design radar systems.
An important task in designing CRSs is to use robust signal processing algorithms and accurate definition of signal parameters. To this end, theory and methods of experimental investigations of stochastic processes are attracted to design the CRS. The theory of statistical estimates, for example, can be used for analyzing regularities to design and construct optimal and quasi-optimal meters of statistical parameters of stochastic processes. At the same time, significant attention is paid to investigation of systematic and random errors of statistical parameter definition as a function of considered time interval and noise level.
A detailed analysis of various procedures and methods to measure and estimate the main statistical parameters of stochastic processes, such as mean (or mathematical expectation), variance, correlation (covariance) function, power spectral density, probability density functions, spikes of energy spectra, etc., is presented. Analog and discrete procedures and methods for measurements and errors, which are characteristic of these procedures and methods, are investigated. In addition, structural block diagrams of digital meters are considered. Structural block diagrams of optimal meters to define the mathematical expectation (mean), variance, and parameters of the correlation (covariance) function are discussed. The variance of estimations and biases of the earlier-mentioned parameters is measured. A procedure to measure the mathematical expectation (mean) and variance of nonstationary stochastic process under robust signal processing used in CRSs is identified. General formulas for definition of biases and variances of statistical parameter estimations are also presented for direct analytical calculation.
I would like to thank my colleagues in the field of robust signal processing in radar systems for useful discussion about the main results, in particular, Professors V. Ignatov, A. Kolyada, I. Malevich, G. Manshin, D. Johnson, B. Bogner, Yu. Sedyshev, J. Schroeder, Yu. Shinakov, A. Kara, Kyung Tae Kim, Yong Deak Kim, Yong Ki Cho, V. Kuzkin, W. Uemura, Dr. O. Drummond, and others.
I would also like to express my gratitude to my colleagues from the Department of Information Technologies and Communications, Electronics Engineering School, College of IT Engineering, Kyungpook National University (KNU), Daegu, South Korea, for useful remarks and comments and their help in completing this project.
This research was supported by the Kyungpook National University Research Fund, 2010.
AlotofcreditisalsoduetoNoraKonopka,KariBudyk,RichardTressider,SuganthiThirunavukarasu, and John Gandour as well as to the entire staff at CRC Press, Taylor & Francis Group, for their encouragement and support.
Last, but definitely not least, I would like to thank my family—my lovely wife, Elena; my sons, Anton and Dima; and my dear mom, Natali—for putting up with me during the writing of the manuscript. Without their support, this book would not have been possible!
Finally, I wish to express my lifelong, heartfelt gratitude to Dr. Peter Tuzlukov, my father and teacher, who introduced me to science.
Vyacheslav Tuzlukov
Preface |
xvii |
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